Polish debugging

Conditions.Rmd

@@ -2,7 +2,6 @@
 
 ```{r, include = FALSE}
 source("common.R")
-options(rlang_trace_top_env = rlang::current_env())
 ```
 
 ## Introduction

DESCRIPTION

@@ -32,4 +32,5 @@ Imports:
     zeallot
 Remotes: 
     hadley/emo,
-    r-lib/lobstr
+    r-lib/lobstr, # crashes with released versio
+    r-lib/rlang # needed for entrace + last_trace()

Environments.Rmd

@@ -811,6 +811,8 @@ There is one last environment we need to explain, the __caller__ environment, ac
 
 To fully understand the caller environment we need to discuss two related concepts: the __call stack__, which is made up of __frames__. Executing a function creates two types of context. You've learned about one already: the execution environment is a child of the function environment, which is determined by where the function was created. There's another type of context created by where the function was called: this is called the call stack.
 
+<!-- HW: mention that this is actually a tree! -->
+
 ### Simple call stacks
 \indexc{cst()}
 \indexc{traceback()}

common.R

@@ -14,6 +14,8 @@ knitr::opts_chunk$set(
   fig.show = "hold"
 )
 
+options(rlang_trace_top_env = rlang::current_env())
+
 options(
   digits = 3,
   str = strOptions(strict.width = "cut")

debugging.R

@@ -0,0 +1,9 @@
+f <- function(a) g(a)
+g <- function(b) h(b)
+h <- function(c) i(c)
+i <- function(d) {
+  if (!is.numeric(d)) {
+    stop("`d` must be numeric", call. = FALSE)
+  }
+  d + 10
+}